- Just the very fact that Adam was ripped from his perfect life at his normal school and forced to attend an animal school, where every day of his life became a living Hell.
- The fact that Ingrid's obsessive crush on Adam will never be returned, not only due to Adam not being interested but also due to the fact that it will never work, on account of her being a giraffe and him being a human. Plus, shes the weakest member of the pack.
- Principal Pixiefrog is still not married and can't find love. This is so bad that he talks about it all the time and his love life (or lack thereof) way-too-often interferes with his work.
- Coach Gills has also gone on a few sad monologues about her not having any friends, even as an adult. Horace wants to be her friend, but Gills says that their relationship is strictly professional.
- Ingrid delivered Adam a sad story about how he mistreated Jake in "The "A" Word", by using an offensive term around him. However, this kind of gets ruined, when you know the whole story. Adam didn't know the term was "offensive" first of all, and in the end, we learn that term wasn't offensive at all and Jake was just getting mad over stupid reasons.
- The episode "Two Tons of Fun" ended with Mr. Hornbill being rejected by Mrs. Tusk in the rudest and most hurtful way ever and there being no redemption for him.
- Adam just could not catch a break in "Supplies Party". It was mentioned at the start of the episode that his 6th birthday was ruined when he wet his pants in front of everybody and cried about it as everybody (including Chad; excluding Kerry) laughed at him. The same shit happened again in this episode on his 12th birthday, where Adam spilled a drink on his pants and cried like a baby, getting Chad to laugh at him and motivating every other kid except for Kerry and his animal friends to join the bandwagon and laugh with him. Thankfully, it ended on a positive note when Kerry and his animal friends stood up for him.
- In "I Got a Brand New Aptitude", Adam and Jake learning that they will never achieve their dreams, as they're inevitable futures have already been decided for them. There was an entire depressing musical number called "What's the Point?", which really went in-depth about how sad their lives are. In fact, this is outright confirmed in this series finale where they officially become zoo animals.
- And dont forget about Rufus. Poor Rufus.
- Little Lord Saucypants used to be Dobie Broadway Juniors faithful companion, until Dobie stopped working and enslaved his poor monkey to pay for his mansion. Thankfully, Adam and Jake put Dobie back on the map and hired human servants again.
Tearjerker / My Gym Partner's a Monkey
All sad moments and concepts in the series. Note that 90% of the show's episodes have downer endings, especially for our main character, so there's bound to be a lot on here.